Screw press



Feb. 11, 1969 w. H. COMBs ET AL 3,426,677

SCREW PRESS Filed Sept. 20. 1966 IN VEN ()RS. WILLIAM H. COMBS SAM N. CRAIG LANCE C. BARLAND ATTORNEYS.

Feb. 11, 1969 w COMES ET AL 3,426,677

SCREW PRESS Filed Sept. 20. 1966 Sheet of 2 I 68 72 a I8 INVENTORS.

F/g.4 WILLIAM H. COMBS SAM N. CRAIG LANCE c. BARLAND ATTORNEYS.

United States Patent 6 Claims ABSTRACT OF THE DISCLOSURE A press for extracting water from a wet solids is provided, wherein the wet solids enter a chamber through a slurry passage, and are contacted by a rotating lifting screw which forces the wet solids upwardly, against a foraminous shell, whereby the pulpy material undergoes a squeezing action, for removing water therefrom.

This invention relates generally to presses for extracting water from wet solids, and particularly to presses of the type aforesaid having a lifting screw turning in a tubular screen housed in a water tight chamber having a slurry feed connection and a drain connection for water separated from the solids.

An important object of the invention is to provide improved means for conducting a slurry of waste material from said feed connection to said lifting screw.

Another object is to provide a slurry passage (leading from said feed connection to the lower extremity of the lifting screw) which is in constant communication with water accumulated in said chamber so that a thick slurry, immediately upon entering said passage, is thinned out sufliciently to flow properly.

Another object is to provide such a slurry passage which relieves high pump pressure at said feed connection so that any tendency for the pressure to be transmitted upwards along the screw is greatly reduced.

Other objects of the invention will become apparent when the following description is read with reference to the accompanying drawings, in which:

FIGURE 1 is a front elevation of a water press constructed in accordance with the invention;

FIGURE 2 is a section on line IIII in FIGURE 1;

FIGURE 3 is an enlarged section on line III-III in FIGURE 2;

FIGURE 4 is an enlarged section on line IV-IV in FIGURE 3; and

FIGURE 5 is a section on line VV in FIGURE 4.

Referring to the drawings, the press constructed in accordance with the invention is mounted upon a floor supported frame 10, being thereby inclined at an angle of approximately sixty degrees to the horizontal. The shell, generally designated 12, is provided with a bottom wall 14 and opposite side walls 16 and 18. The lower extremity of the shell is suitably flanged and fitted with a removable plate 20, and the top of the shell is suitably flanged and fitted with a removable plate 22. The shell 12 and the plates 20 and 22 are arranged to afford a water tight construction. At the very bottom of the shell is a drain line 24, and extending from the bottom wall 14 of the shell, intermediate the opposite ends thereof, is an overflow connection 26.

Referring particularly to FIGURES 3 and 4, aflixed to the side wall 16 of the shell, at the lower extremity thereof, is a bar 30 from which there extends a bracket 32 secured to the bar 30 by means of screws 34. Mounted upright upon the bracket 32, on the central axis of the shell 12, is a guide pin 36. Fitted over the guide pin 36 and seated upon the bracket 32 is a retainer, generally 3,426,677 Patented Feb. 11, 1969 designated 38, made in its entirety of foraminous sheet material. The retainer is provided with a main body portion 40 including a base wall 42 from which there rises an upright circular side wall 44. The top of the main body portion 40 is open, as at 46. Communicating with the interior of the main body portion 40 of the retainer 38 through the circular side wall 44 and extending tangentially therefrom is a square tubular section 48. The bottom wall of the section 48, designated 50, is a planar extension of the base wall 42 of the main body portion 40 of the retainer 38.

The outer end portion of the section 48 is fitted over a sleeve 56 having a flange 58. A gasket 60 is provided between the flange 58 and the wall 18 of the shell, and a gasket 62 is provided between the wall 18 of the shell and a mounting plate 66. Screws 64 extend through the flange 58, gasket 60, wall 18 of the shell, and gasket 62 and are threaded into a mounting flange 66. Studs afiixed to the mounting flange 66 extend therefrom through a gasket 69 and a pipe flange 70 secured to the mounting flange 66 by means of nuts 72 threaded on the studs, designated 68. The flange 70 is on the end of a slurry line 74.

The lower end portion of a tubular screen 76 extending longitudinally of the shell is nested in the main body 40 of the retainer 38, a portion of the circumference thereof being removed for communication of the interior of the screen with the interior of the section 48 of the retainer 38. The upper end portion of the screen 76 is secured to a head 78 mounted upon the upper end portion of the shell. The base wal 80 of the head is provided with an opening through which the interior of the screen communicates with the interior of the head. A chute 88, affixed to the opposite side walls of the head, designated 82. extends downwardly therefrom, as shown.

Within the screen 76 is a screw provided with a hollow shaft and a ribbon flight 91. Pressed into the lower end portion of the shaft 90 is a bearing retainer 92 secured by a screw 94 and provided with a cap 96. Within the bearing retainer is an oilless bearing 98 provided with a threaded central bore 100 and several radially extending bores 104. The upper end portion of the shaft 90 extends through the top wall of the head, designated 86,

and is journaled in a roller bearing 108 housed in a sleeve 106 mounted on the top wall 86 of the head. Upon the upper end of the shaft 90, within the head 78, is mounted a compression cone 112, made in two parts and secured to the shaft by means of screws 114, and a bursting cone 116, made in two parts and secured to the shaft by means of screws 118. Mounted upon the upper extremity of the shaft 78 is a change speed unit connected by a drive 122 to an electric motor 124, the motor being supported upon a bracket 126.

In the operation of the press a slurry of wet solids, for example, waste material, is fed into the press through the slurry line 74. Immediately upon issuing from the sleeve 56 the slurry comes into contact with water accumulated in the bottom of the shell to the level of the overflow connection '26. The water enters the section 48 through the perforations in the bottom, side and top walls thereof and thereby thins out the slurry so that it flows easily through the section 48 to the lower end of the ribbon flight 91, which is aligned with the passage through section 48.

The electric motor 124, through drive 122 and change speed unit 120, drives the screw in a direction for lifting the solids to the top of the ribbon flight 91. As the solid waste rises above the overflow water level, water drains therefrom and flows to the bottom of the shell, from whence it is drawn off through the drain line 24. If the water level rises above the desired level, it is discharged through the overflow connection 26. As the waste is forced upwardly it forms a solid mass compacted against the cone 112, and as it rises still farther this mass is spread and broken up by the bursting cone 116 and gravity discharged through the chute 88.

It will be apparent that the arrangement may be used either for a close coupled system, which does not use a slurry pump to pump material from the pulper to the press, or for a remote system, which does use a pump.

The continuous supply of water to the passage 48 assures a thin enough slurry to permit proper flow to the base of the screw, which is of particular importance in an arrangement wherein the press follows a vertical pulper and a horizontal slurry passage, i.e., where gravity is of little or no assistance to flow.

In a remote system, i.e., where the press is remote from the pulper, a high pressure pump must be used. The foraminous walls of the tangential section 48 are of particular importance in such a system because they relieve high pressure at the earliest possible moment, and thereby reduce the tendency for the pressure to be transmitted upwardly along the ribbon flight.

It will be noted that the screws 90-91 and screen 76 may be removed without disturbing the slurry infeed connection or other piping. In addition, the guide pin may positively centered exactly in the screen, assuring concentricity of the screen .and screw. It will be noted that no solids can be passed to drain, and that the lower extremity of the ribbon flight is lined up with the passage through the tangential section 48, resulting in an optimum pick-up condition.

What is claimed is:

1. In a press for extracting water from a slurry of solids, the combination comprising a generally upright elongated shell having a fluid tight section at the bottom thereof, an infeed connection for slurry, a drain connection for removing from said shell water separated from said solids, a revolvable lifting screw extending longitudinally within said shell including a central shaft and a ribbon flight spiraling thereabout, a tubular screen circular in transverse section extending about said screw, a retainer including a main body portion having a bottom wall extending across the lower extremity of said screen, and having a tubular section made of foraminous sheet material extending from said screen, the lower terminal edge of said ribbon flight being close adjacent said bottom wall, the inner end of said tubular section being in communication with the interior of said screen, :and the outer end of said tubular section being in communication with said infeed connecton, and means carried by said shell and mountng said retainer, and wherein a circular rim rises from the bottom wall of the retainer and is open at the top thereof, the lower end portion of the screen is fitted into said rim through the open top thereof, and the inner end of the tubular section communicates with the interior of the screen through registering openings respectively in said rim and screen.

2. The combination according to claim 1, wherein said tubular section extends tangentially from said screen.

3. The combination according to claim 1 wherein the retainer is made in its entirety of foraminous sheet material.

4. In a press for extracting water from a slurry of solids, the combination comprising a generally upright elongated shell having a fluid tight section at the bottom thereof, an infeed connection for slurry, ad rain connection for removing from said shell water separated from said solids, a revolvable lifting screw extending longitudinally within said shell including a central shaft and a ribbon flight spiraling thereabout, a tubular screen circular in transverse section extending about said screw, a retainer including a main body portion having a bottom Wall extending across the lower extremity of said screen, and having a tubular section made of foraminous sheet material extending from said screen, the lower terminal edge of said ribbon flight being close adjacent said bottom wall, the inner end of said tubular section being in communication with the interior of said screen, and the outer end of said tubular section being in communication with said infeed connection, and means carried by said shell and mounting said retainer, and wherein the infeed connection includes a sleeve connected with the outer end of the tubular section, said sleeve extending inwardly from the wall of the shell along 'said tubular section a distance which is short when compared with the length of the tubular section so as to leave substantial areas of the foraminated walls of the tubular section exposed for penetration of water therethrough to the interior of the tubular section.

5. In a press for extracting water from a slurry of solids, the combination comprising a generally upright elongated shell having a fluid tight section at the bottom thereof, an infeed connection for slurry, a drain connection for removing from said shell water separated from said solids, a revolvable lifting screw extending longitudinally within said shell including a central shaft and a ribbon flight spiraling thereabout, a tubular screen circular in transverse section extending about said screw, a retainer including a main body portion having a bottom wall extending across the lower extremity of said screen, and having a tubular section made of foraminous sheet material extending from said screen, the lower terminal edge of said ribbon flight being close adjacent said bottom wall, the inner end of said tubular section being in communication with the interior of said screen, and the outer end of said tubular section being in communication with said infeed connection, and means carried by said shell and mounting said retainer, and wherein the means mounting the retainer includes a bracket aflixed to a wall of the shell, the bottom wall of the retainer is seated upon said bracket, one of the screw shaft and bracket mounts a pin, and the other mounts a bearing fitted over said pin, and said pin and bearing are operative to center the screw in said screen.

6. The combination according to claim 5 wherein the pin extends upright from the bracket, the bearing is of the sleeve type and is mounted in a bearing retainer, the screw shaft is a tubular member, and the bearing retainer is fitted into the lower extremity of the screw shaft.

References Cited UNITED STATES PATENTS 488,583 12/ 1892 Sobotka et al. -145 1,076,995 10/ 1913 Renneburg 100-145 1,130,149 3/1915 Conway 100-145 X 2,960,926 11/1960 McKee 100-117 2,970,776 2/1961 Buckman 100-1l7 X 3,035,511 5/1962 Hayes 100-117 3,062,129 11/1962 Wandel 100-117 X LOUIS O. MAASSEL, Primary Examiner. 

